The activity, the heat of mixing, the concentration fluctuation in the long wavelength limit (Scc(0)) and the chemical short range order parameter (CSRO) have been studied as a function of composition in LiMg molten alloys by using first order quasi-chemical (QC) theory. The interchange energy has been considered a function of temperature and thus various thermodynamic quantities are calculated at elevated temperatures. The study reveals that though LiMg is considered a simple regular alloy, its various thermodynamic properties deviate from the ideal solution behaviour. Scc(0) computed at different temperatures from QC-theory are found to be smaller than the ideal values and heterocoordination in the nearest neighbour shell is found to exist through the entire concentration range. On the other hand, Scc(0) computed directly from the measured activity data indicates that the LiMg liquid alloy behaves as a segregating system for smaller content of Li (CLi≤0.3). The building of heterocoordination starts around CLi≥0.3 and remains for the rest of the compositions.
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